Australia's first outbreak of H5 bird flu in wild birds has held at 17 confirmed detections across three states, with no infection reported in commercial poultry, the federal agriculture department said in its latest update. As of 9am on 19 July, the virus had been found in wild seabirds at 10 sites in Western Australia, five in South Australia and two in New South Wales.
The national committee that manages emergency animal diseases has kept the poultry industry on heightened biosecurity for up to a further two weeks while it settles longer-term guidance. The measures include voluntary steps such as housing free-range birds where it is practical. There have been no human cases in Australia from this outbreak, and the department assesses the risk to people as low.
The strain is H5N1 clade 2.3.4.4b, the version that has moved through wild bird populations on every other continent over the past four years and reached Australia only this year. It arrived in migratory seabirds, with the first detection a brown skua on the Western Australian coast in June, and has mostly stayed in giant petrels and other seabirds since.
The concern for the department, and for shoppers, is what happens if the virus moves from wild birds into commercial flocks. Australia's chief veterinary officer, Beth Cookson, said there were no detections in poultry or in the agricultural production system, and no evidence of mass die-offs on the mainland. Earlier bird flu outbreaks in Australian poultry, caused by different strains, have forced the culling of large numbers of hens and led to temporary limits on egg sales.
The virus has already done severe damage in Australian territory further south. In findings published on 18 June, the Australian Antarctic Program confirmed H5N1 at Heard Island and McDonald Islands, where it killed an estimated 13,000 southern elephant seal pups over the summer, along with hundreds of king penguins. Those islands are thousands of kilometres from the mainland, and the deaths there are among wildlife rather than livestock, but they show how lethal the strain is once it takes hold in a crowded breeding colony.
For the poultry industry, the response so far rests on keeping the two apart: the wild birds carrying the virus, and the sheds where commercial flocks are raised. That is why the heightened biosecurity has been extended rather than lifted. Producers have not been ordered to house free-range birds, a step that would carry its own cost and animal-welfare questions, and the committee has left it as a voluntary measure for now.
The department has said it will keep updating the detection count, which last moved on 17 July and held at 17 through the weekend. The number to watch is not that one. It is the first case, if it comes, in a commercial flock.
